Philadelphia's population increased by 6,098 residents between 2016 and 2017, the 11th straight year of growth that the city enjoyed after decades of population decline.
Still, not all the news from U.S. Census Bureau population estimates, released Thursday, was positive. For example, more people moved out of the city than moved in. The population increase came from birthrates exceeding death rates.
And the city's growth continues to lag others, especially in the South and West.
Here are five things to know about what the census numbers say about our area:
Philadelphia’s growth streak continues, but don’t get excited
The Philadelphia population was listed as 1,580,863, according to census figures, which measured the period between July 2016 and July 2017.
The last time the city registered an overall population loss was 2006, when the population dropped by 2,151 people to 1,488,710.
Economists taking their first look at the numbers echoed the restrained reaction offered by Mark Zandi, chief economist at Moody's Analytics: "Philadelphia is holding its own, which is OK. It's not dynamic, but it's not losing overall."
Lauren Cox, communication director for the Philadelphia Department of Commerce, said the census numbers are "an encouraging sign for our city's overall economic health."
The city is growing faster than the suburbs — and nowhere suffers more than South Jersey
Since 2010, Philadelphia's population gains have outpaced those of its suburban Pennsylvania counties, while growth has been nonexistent in South Jersey.
In the current estimates, only Chester County registered a higher percentage growth in population than Philadelphia — 3.9 percent compared to 3.4 percent. It wasn't clear to experts contacted Wednesday what accounted for Chester County's uptick.
As for why South Jersey continues to show little population growth, however, there were a few guesses.
"The millennial generation is so large, and the story of millennials is, they like to live in highly dense areas," said Brandon McKoy, director of government and public affairs for New Jersey Policy Perspective, a nonpartisan Trenton think tank. "And South Jersey has few of those. Central and North Jersey is where the density is, and that's where people are headed."
Beyond that, said David Elesh, emeritus sociology professor at Temple University, South Jersey has still not recovered from the recession. "They got just demolished in housing, with so many foreclosures and short sales," he said. "That hangover lasts a long time."
In Philadelphia, more people moved out than immigrants moved in
The city brought in 10,240 immigrants between 2016 and 2017, Census figures showed. But among people moving within the U.S., 10,817 more people moved out of Philadelphia than moved in, resulting in a net loss of 577 people.
That statistic belies the current impression of Philadelphia as a vibrant place that beckons young people and highly accomplished professionals.
How can the city be attracting and repelling people at the same time?
What happens, noted Kim Goyette, chair of the Temple sociology department, is that Philadelphia's "high-education landscape" indeed calls to young, smart people.
"But once they start families, they move out."
This has been the pull-push dynamic that's blessed and cursed the city for years, experts say.
Simply put, the city's school system drives out parents once their children reach age 5, experts say.
Said Villanova University economist Cheryl Carleton, "It's great when you're young, but once you have school-age kids, it all gets dicey. The public schools are not doing well, and people don't see that changing.
"The city has a lot going for it, with good medical facilities, colleges, and parks. But the schools make it difficult for people to stay."
In Philadelphia, for every 100 families with children that move in, 270 are moving out, according to research by economist Neeta Fogg of the Center for Labor Markets and Policy at Drexel University.
Philadelphia is not the only one losing residents
Of the 25 largest counties (Philadelphia ranks 23rd), only eight had a net domestic migration gain in 2017. Los Angeles County, the nation's largest with 10.2 million residents, had a net loss of 91,680, an average of 251 more people moving out per day than moving in.
Cook County, Ill., home to Chicago, had a net loss of 65,871. In fact, only two of the nation's 10 largest counties had a net gain in domestic migration: Maricopa County, Ariz., home to fast-growing Phoenix, posted a gain of 38,852. (Its overall population gain of 73,650 was highest in the country.)
Riverside County, Calif., had a net gain of 19,586. The home counties of Houston, San Diego, Miami, Brooklyn, and Dallas, as well as Orange County, Calif., posted net domestic migration losses.
Where People Are Moving Within the U.S.
So if more people are moving out than moving in, how did Philadelphia gain population?
Something called natural increase — the number of births minus the number of deaths.
In 2017, there were 21,776 births and 15,026 deaths in Philadelphia, a natural increase of 6,750. That figure accounts for all of the city's population gain last year. Natural increase also fueled the population gains of other large counties, which, like Philadelphia, suffered from large domestic migration losses. Los Angeles, Harris (Houston), San Diego, and Kings (Brooklyn) Counties all grew in population by having strong natural increase numbers that covered for net losses in people moving domestically and internationally.